Tyres are known in which the tread has circumferential grooves defining a number of raised elements, such as circumferential ribs and/or blocks, at least some of which have, on the outer surface, a number of sipes at various angles with respect to a motion direction of the tyre. The sipes, which divide the relative raised elements into respective numbers of relatively flexible lamellar blocks, serve not only to break up the film of water on wet road surfaces, for better tyre-ground contact in the rain, but also, and above all, to trap snow, by flexing, between adjacent lamellar blocks to improve traction, braking, and lateral stability on snow.
While improving grip of the tyre on wet road surfaces or snow, siped raised elements, on the other hand, obviously have the drawback—given the flexibility of the relative lamellar blocks, and especially on dry road surfaces—of impairing tyre performance in terms of handling capacity, traction, and braking.